Amplifi HD LAN and WLAN both die

My setup is three Amplifi HDs: One is connected to my modem and acts as router. The other two are connected by ethernet cables to the router and act as mesh points. This has been working fairly well for a year or so although my family members are hard to please when it comes to wireless network speeds...

For the last days, approximately since updating to firmware 3.1.0, the complaining about slow and unstable wireless networking has increased in intensity.

I must admit that my Samsung Galaxy S8 has joined in and complains regularly that although it is connected to the wireless network, «the internet is maybe not available». And I have to agree, when the phone says that the internet is maybe not available, it really isn’t - not on the phone, anyway. My iPad Pro, on the other hand, is generally happy. So, a hard case to investigate.

However, on Thursday afternoon and again late Saturday evening, the following happened: All network access ceased for the entire house - LAN as well as WLAN. No SSIDs broadcast, no LAN working, and the Amplifi HD router showed the Amplifi logo and four dashes instead of the logo and time/date. Cutting the power to the router and then re-energizing it fixed the network (the mesh points did not need to be powered down - just the router).

This is, of course, a major problem. If I can’t trust the router to stay online, I’ll have to chuck it (and the mesh points) out, but clearly something is not quite right. Is it due to the latest firmware update. Could it be a hardware failure? How do I figure that out?

@tom-nestli What mode is you AmpliFi operating under (DHCP or Bridge)? Also might be worth trying to do a full reset of all the units and setting them up again (if it is not too much hassle losing all your original settings) to see if that would fix it.

I've now also factory reset the three Amplifi HDs (the router and the mesh points). Back up from the web interface helped restoring the router. It backed up DHCP settings (static leases), but it did not back up port forwards, so that was a bit of work setting them back up (ability to do setup like that on the web interface would make it easier than doing it on the cell phone, but that is unfortunately not possible. Why?).

I'll let the system do its thing for a day or three and then report back here.

I had seemlingly the same problem.
For the time you should downgrade your firmware to firmware version 3.0.1 (via amplifi.lan) and all will return to working order again. Currently going to try a beta firmware which hopefully fixes things.
I also have an S8 by the way

Short update for @Tom-Nestli :
After the help of @UI-Brett and Becky from the helpdesk I'm running the beta firmware for 30 minutes and the connection is still stable. Looks real promissing!
Current firmware version I'm testing: 3.1.1rc3

After factory resetting the HDs I've not had the LAN and WLAN die on me (but then it's only been less than 24 hours).

However, I have had DNS problems arising during the night. I did have DNS problems earlier as well, and resolved those by Bypassing the DNS cache (from the web UI). Bypassing the DNS cache now seems to have resolved the DNS problem.

I've noticed that version 3.1.1 has been released. It's not yet available for me - according to the web UI (support->update), but I'll keep a look out for it and update when available.